Display apparatus that causes display device to enlarge or reduce image according to user gesture detection result from detector, and image forming apparatus

A display apparatus comprising:

• a display device;
• a detection device that detects a gesture of a user;
• and
• a control device including a processor, and configured to act, when the processor executes a control program, as a controller that:
• causes the display device to display a predetermined image in a display region;
• calculates, upon detecting a predetermined loop shape and a user's eye located inside the loop shape, according to a detection result from the detection device, a relative size of the user's eye with respect to a size of the loop shape at a time of the detection, as a reference size;
• causes the display device, when the controller detects that the relative size has changed, according to the detection result from the detection device, and when the changed relative size is larger than the reference size, to enlarge the predetermined image, in proportion to a difference between the changed relative size and the reference size;
• and
• causes the display device, when the controller detects that the relative size has changed, according to the detection result from the detection device, and when the changed relative size is smaller than the reference size, to reduce the predetermined image, in proportion to a difference between the changed relative size and the reference size.